The invention relates to a hydraulic clutch, particularly to such a clutch having a valve opening controlled by a valve lever actuated by an electromagnet.
A hydraulic clutch has been disclosed in DE-B-28 04 859 by the applicant. In this design, an electromagnet is mounted in the end wall of the clutch in a fixed manner so as to be rotatable by means of a ballbearing and the valve lever which is located in the reservoir chamber bears in its central area, i.e. the area near to the axle, a permanent magnet which is located in the area of effect of the electromagnet with an intermediate gap. The valve lever can thus be actuated by acting on the electromagnet, the permanent magnet not being attracted but rather repelled so that the gap is maintained. Between the electromagnet and the permanent magnet there is a sealing plate which increases the distance and impedes the magnetic flux. Therefore, the electromagnet must be given larger dimensions which entails disadvantages in terms of weight and costs. In addition, with this design it is disadvantageous that this type of magnet control cannot be used for a plurality of valve levers within the reservoir chamber as has been disclosed in DE-A-42 05 523 by the applicant. Moreover, because of its minimum radial dimensions a relatively large ballbearing with corresponding weight is necessary for this magnet which is located inside the ballbearing.